Drilling Fleet (Impairment held and used) (Details) $ / shares in Units, $ in Millions	3 Months Ended
Mar. 31, 2020 USD ($) $ / shares
Impairment of assets held and used
Loss associated with impairment, net of tax (per share) \| $ / shares	$ 0.23
Midwater floaters
Impairment of assets held and used
Impairment of in use assets \| $	$ 31
Loss associated with impairment, net of tax (per share) \| $ / shares	$ 0.05
Loss associated with in use asset impairment, tax effect \| $	$ 0

The aggregate amount of write-downs for impairments recognized during the period for long lived assets held for use (including those held for disposal by means other than sale).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Period Type:	duration